Vitamin D, calcium supplements could reduce falls in women, not men

A daily supplement of vitamin D and calcium cut the rate of falls
in elderly women by 50 per cent, but not men, reports a new study.

Several earlier studies have linked vitamin D and calcium
supplements to fewer falls, as well as lower risk of osteoporosis
and osteoporotic fractures.

The new double-blind, randomised, placebo-controlled study,
published in the Archives of Internal Medicine​ (Vol. 166,
pp.424-430) supplemented the diets of 199 men and 246 women with
700 IU of cholocalciferol (vitamin D3) plus 500 mg of calcium in
the form of calcium citrate malate, or placebo.

The study population was analysed in terms of sub-groups for
men, women, active and inactive, and serum levels of
25-hydroxyvitamin D (the non-active 'storage' form).

After three years of supplementation the researchers observed:
"Long-term dietary cholocalciferol-calcium supplementation
reduces the odds of falling in ambulatory (mobile) older women by
46 per cent, and especially in non-active women by 65 per
cent."​

The same level of supplementation had no effect on men,
regardless of how active they were.

Interestingly, there was no significant difference in the serum
25-hydroxyvitamin D levels in the supplemented or placebo women (28
versus 25 nanograms per millilitre) or men (33.2 versus 32.8
nanograms per millilitre).

The difference between the sexes was rationalised in terms of
women have lower muscle strength than men and are thus more likely
to fall.

It could also be argued that the difference between the number
of falls of active and less-active women is not due to the
supplements but is in fact due to the fact that more active people
put themselves at increased risk simply by being more active, a
point the researchers admit.

Another limitation is that the main findings are linked to
subgroups of the sample population, but the original study design
was not powered to specifically detect the effect of sex, activity
and serum 25-hydroxyvitamin D levels.

Despite these limitations, the double-blind, randomised,
placebo-controlled design is a big strength, and the researchers
argue that the results have clinical significance.

"We show a significant reduction in the odds of falling in
ambulatory older women with a very inexpensive, well-tolerated, and
simple supplementation with cholocalciferol-calcium,"​ wrote
lead author Heike Bischoff-Ferrari from the University Hospital
Zurich.

These results support a previous study by the same group, which
reported a 60 per cent reduction of fractures from supplements.

The recent WHI study also supports these results, despite some
misrepresentation by the mainstream media. For those women who
actually adhered to the supplementation program, taking a daily
supplement of 1000 mg of elemental calcium in the carbonate form
and 400 IU of vitamin D3 was linked to a 29 per cent reduction in
fractures.

The combination of vitamin D and calcium has long been
recommended to reduce the risk of bone fracture for older people,
particularly those at risk or suffering from osteoporosis,
estimated to affect about 75 million people in Europe, the USA and
Japan.

This use of the supplements is widely accepted by the general
public, with calcium supplements reported to be the biggest seller
in the US supplements industry, with annual sales of about $993
(€836) million in 2004, according to the Nutrition Business
Journal.